AU612965B2 - Polymeric thickeners and their production - Google Patents

Description

COMMONWEALT OF AUSTRALIA PATENT ACT 1952 COMPLETE SPECIFICATION (Original) FOR OFFICE USE 61296.5 Class Int. Class Application Number: 6o /6 Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: o 9 o o Name of Applicant: 9 o".Address of Applicant: 0948 *Actual Inventor(s) '9r ALLIED COLLOIDS LIMITED P.O. Box 38 Low Moor, Bradford, West Yorkshire BD12 OJZ,

ENGLAND

David FARRAR Malcolm HAWE Address for Service: DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

1r 4( E Complete Specification for the invention entitled: "POLYMERIC THICKENERS AND THEIR PRODUCTION" The following statement is a full description of this invention, including the best method performing it known to us -1- 1A Allied Colloids Limited 60/2493/02 Polymeric Thickeners and their Production It is known that aqueous media can be thickened by the presence of high molecular weight synthetic polymers either in solution or in the form of swollen particles.

If the polymers are in solution the thickening is probably due to entanglement of polymeric chains. If the polymers are swollen the thickening is probably due to inter-particulate attraction and solvent immobilisation.

It is known that thickening in some instances can be improved by including in the polymer pendant hydrophobic groups, the improvement apparently being due to association between the hydrophobic groups in adjacent 15 molecules and the polymers containing such groups are 9. often referred to as associative thickeners.

GB 1,167,524 describes thickeners that are said to be effective in solutions of surface active agents and that are copolymers of at least one ethylenically 20 unsaturated monomer with a comonomer that is, for *9*9 instance, an acrylic ester or an allyl ether of a polyalkoxylated alcohol that may be aliphatic or aromatic. This polyalkoxylated alcohol thus provides °the pendant hydrophobic groups. Particular allyl ethers of this general type, and copolymers formed from them, are also described in GB 1,273,552.

All the examples in these patents of copolymers using allyl ether show the copolymer to be soluble in water. The comonomer with the ether or ester is said to be acrylic acid, acrylamide, vinyl pyrollidone or maleic anhydride or a blend of maleic anhydride with a compound which normally copolymerises in alternating sequence.

The use of maleic anhydride alone or in such a blend will tend to give a low molecular weight compared to the 2 values currently available when copolymerising, for instance, acrylic acid.

In most of the examples the comonomer is maleic anhydride, optionally with methyl vinyl ether, but in example 12 of GB 1,167,524 and example 8 of GB 1,273,552 the allyl ether is copolymerised with acrylic acid to form a water soluble polymer. The information in each example suggests that the molecular weight is low.

In all of the examples showing the use of allyl ethers, polymerisation is conducted by precipitation polymerisation. Thus polymerisation is conducted in a liquid that is a solvent for the monomer but not for the polymer, so that polymer is precipitated out of the solution during polymerisation. This technique tends to 15 produce rather low molecular weights.

The intention to form low molecular weight compounds is emphasised by example 13 of GB 1,167,524 in which a copolymer is formed by aqueous solution polymerisation of acrylamide and an acrylic ester with a polyethoxylated nonyl phenyl alcohol since isopropanol is included in the polymerisation mixture. This will ensure that a relatively low molecular weight polymer is produced.

It is well known that allyl monomers polymerise much less readily, and yield copolymers of lower molecular weights, than acrylic or other vinyl monomers. In US 4451628 allyl sulphonate is used to depress molecular weight. Another allyl monomer is diallyl dimethyl ammonium chloride and it is well known that polymers of this generally have a maximum molecular weight of below 500,000.

The fact that the use of allyl monomers causes the resultant homo- or co-polymer to be of low *molecular weight is discussed frequently in the literature, for instance in "Functional Monomers" Volume 1 edited by Yocum and Nyquist pages 384 to 387. It is stated in L I Ithis that allyl monomers polymerise with difficulty to give products of low molecular weight and their presence will retard both the rate and degree of polymerisation of other copolymerisable monomers. It is stated that the polymerisation kinetics of allyl monomers are determined by degradative chain transfer which results in the formation of a stable radical that has low activity for chain propogation. The article describes ways of trying to obtain higher molecular weights but the highest value i 10 obtainable is said to have a degree of polymerisation of the order of 1,000 to 10,000. The molecular weight is Stherefore still low by the standards of acrylic or other vinyl monomers since these can easily be polymerised to molecular weights in the range 10 million to 30 million, provided chain transfer agent is omitted.

S..,Since the techniques and comonomers that were i specifically described in GB 1,167,524 were all such as i i to lead inevitably to relatively low molecular weight 20r polymers it was reasonable to propose the use of allyl L tr 20 ether monomers. They would be expected to give the sort of molecular weights that clearly were intended to be achieved in the processes of that patent and GB 1,273,552. In practice the products of these patents have not proved commercially very successful.

In marked contrast to these low molecular weight allyl ether and acrylate copolymers has been the commercial success of associative polymers formed solely from acrylic monomers and by techniques that would normally be expected to give high molecular weights.

The literature relating to these polymers generally indicates molecular weights in the range 100,000 (in the presence of chain transfer agent) to several million.

Instead of making the polymers in the presence of a relatively large amount of isopropanol or by precipitation polymerisation or using comonomers such as -a 4 maleic anhydride blends, all of which will tend to give low molecular weights, the successful associative thickeners are generally made by oil-in-water emulsion polymerisation or by aqueous solution or gel polymerisation, and can have very high molecular weights.

If for a particular purpose the highest molecular weights are to be avoided very low amounts of chain transfer agent are incorporated to depress molecular weight but the resultant molecular weights will generally still be well above those made by the processes described in GB 1167524 and 1273552.

In EP 48094 the pendant hydrophobic group is introduced as a polymerisation initiator or chain transfer agent (tending to depress molecular weight) in the polymerisation of acrylamide. In EP 63018 and U.S.

ooo 4,423,199 and 4,524,175 the hydrophobic group is 0 introduced as a substituent in acrylamide.

*o The JP 60-235815A the pendant hydrophobic group is 000 introduced as a vinyl ether.

o 20 The great majority of literature on associative thickeners, and all commercial products, introduces the hydrophobic group as an ester of an unsaturated o oe 006 carboxylic acid (generally (meth) acrylic acid) that is 0 "o copolymerised with one or more monomers that are always vinylic, and are usually (meth) acrylic. Thus in U.S.

°o 3,915,921 and U.S. 4,190,562 the hydrophobic group is introduced as a C 10-30 alkyl ester of (meth) acrylic acid. In U.S. 4,138,381, 4,268,641, 4,384,096 and 4,463,151, EP 13836 and EP 109820 and in GB 1,167,524 an ester is formed between an unsaturated acid and a hydrocarbyl ether of a polyalkylene glycol.

When the polymers are linear it is clear that increasing molecular weight generally gives increasing thickening properties (although it may also give flocculation of suspended solids) and so the use of

I

monomers that make it impossible to obtain high the molecular weights is clearly contra-indicated. In those particular instances where lower molecular weight is desired, if flocculation of suspended solids is to be avoided, then this is best achieved commercially by using the same monomer blend as will give high molecular weight together with a low amount of a chain transfer agent such as a mercaptan.

Similarly, when the polymers are cross linked experience in other polymerisation techniques for making thickeners generally indicates that the best polymer properties are obtained when the cross linked polymer is formed from monomers that, in the absence of cross linking agent, would give the highest possible molecular 15 weight. Thus cross linked polymers should also be formed S from acrylic monomers in the absence of monomers that I will significantly reduce molecular weight.

T 4* The present state of the art therefore is that when ,manufacturing cross linked or, especially, linear Ci te 20 polymers that are to be used for, for instance, thickening the best properties generally follow from the use of monomers capable of polymerising to very high t molecular weights optionally with a chain transfer agent U tt i, 5 such as a mercaptan, allyl monomers are known to be incapable of giving high molecular weights, and the processes in GB 1,167,524 and 1,273,552 clearly all gave linear polymers of molecular weights much less than those that would now be considered to be necessary for satisfactory properties.

Polymers such as those described in EP 13836 are made by oil-in-water emulsion polymerisation and swell or dissolve upon the addition of alkali. They have proved commercially successful but there is still considerable room for improvement in their properties.

-A

14 For instance one use of the polymuers is for thickening aqueous solutions containling atn aectrolyto. Tho Colution.a wlay therefore have relatively high pH. Also they may be usod under conditions of high temperatura. Unfortunately, hibjh pH and/or high teixperature. can result in hydrolysis of the ester linkage by which the hydrophobic group is attached.

A problem that is often encountered commercially with thickeners such as in EP 13836 is that they may cause fodmirig, and p.rint. quality (when used in textile printing pastes) may need imlprovem~ent in some instances.

tit Despite all the experience indicatinq that it is essential to use, when making thickeners, only mononers capable of giving high mclecular weight polymers, we have nov found that a particular clas of new polymers formed from monomers including a particular type of allyl monomer have surprisingly valuable. thickening propcrtios.

A pvlyzvc devording to the invention selected froin polymers that are non swelling and insoluble in water but soluble or swellable in aqueous acid or alkali and cross linked polymers and which polymer is formod Jby polymori.Girg 0 to 90% by weight of wthylenically unsaturated ionic monomer 0 to 90% by weight of ethyleniocally uni~aturatiud subotantially non-ionic monozoor I to 1004 by w.eight of an ethylenically unsaturated monomer that carries a pcndant group BRF whero V B is ethylerioxy, n is zero or a positive Integer, and R is a hydrooarbyl group of 8 to 30 oarbonr, colcted from alkyl, aralkyl, aryl, alkary. and c'jcoloalkyl.

0 to by weiqht of croso linking agont that le polyethylenical ly unsaturated monnner, characterised in that mcnomers a, b, c and d are miixed before. this pnympri~Ation and thit, n~onomfltr ift An Allyl ether of the formuila CH, C11'CHiZOB,,JR where RO is hydrogen or methyl.

7 Throughout this specification all percentages are by weight unless otherwise specified. All intrinsic viscosities are single point intrinsic viscosity as measured at 0.05% polymer concentration in methanol.

The preferred polymers of the invention are made by oil-in-water emulsion polymerisation and are substantially insoluble and non swellable in water at pH 7 but are soluble or swellable in aqueous acid or aqueous alkali and are formed from 5 to 90% of monomer 5 to 90% of monomer 0.5 to 90% of monomer and 0 to of monomer and so the invention is now described with particular reference to these.

The oil-in-water emulsion polymerisation is conducted using sufficient of an appropriate emulsifier, 15 as is conventional. The final polymer is insoluble and substantially unswollen in the aqueous phase of the B° polymerisation mixture but, due to the ionic monomer, is soluble or swellable upon appropriate pH adjustment, o generally to below pH 7 when the monomer is free 20 amine and to above pH 7 when the monomer is free acid. The solubility of the monomers in the aqueous phase may be conventional for oil-in-water emulsion 0.B polymerisation. Generally the blend of monomers, and often each monomer, is insoluble in the aqueous phase but some water solubility can be tolerated provided the *it monomers all migrate during the polymerisation into the micelles of emulsifier.

Monomer is preferably a vinyl, generally tit t acrylic, monomer and may be a co-ionic blend of monomers.

When monomer is anionic upon addition of alkali, the monomer and its amount must be such that addition of alkali renders the polymer soluble or swellable. The monomer is generally a carboxylic monomer as free acid during the polymerisation. The monomer generally contains 3 to 8 carbon atoms. It may be a Y- I r L ~~-.lc~s'ril r:n 8 monocarboxylic acid, a dicarboxylic acid or, for instance, a monoalkyl ester of a dicarboxylic acid. The acid may be selected from acrylic, methacrylic, itaconic, crotonic, fumaric, citraconic acryloxypropionic or maleic acids. Preferably at least 50%, and most preferably 100%, of component is provided by methacrylic and/or acrylic acid, with methacrylic being particularly preferred.

When monomer is cationic, the monomer and its amount must be such that the addition of acid or quaternising compound, renders the polymer soluble or swellable. The monomer generally includes a tertiary amine group as a free base during polymerisation and this is then converted to the cationic form as an acid salt or 15 quaternary ammonium salt. Dialkylaminoalkyl (meth) acrylamides may be used. For instance the aminoalkyl group may contain 2-8 carbon atoms, preferably S* 1,3-propylene, and the other alkyl groups may contain 1 to 4 carbons. The preferred monomers are 20 dialkylaminoalkyl (meth) acrylates. The preferred monomers are dimethylaminoethyl (meth) acrylates and dimethylaminopropyl (meth) acrylamides.

The amount of monomer must be such that the d r blend of components and can be polymerised by oil-in-water emulsion polymerisation to form an emulsion of the polymeric thickener in which the polymer is insoluble and substantially unswollen and non-thickening but that, after polymerisation, the emulsion can be converted by addition of alkali or acid into a viscous system thickened by the polymer. It is generally necessary for there to be at least 10%, usually at least 20% and preferably at least 30% of the ionic monomer. The amount is generally below 70%, usually below Monomer iis preferably a vinyl, generally acrylic, monomer and may be a bland of monomers, Tho TnoflomerA are generally water in"o1tibih. hut ft rninrr proportion of monomer may be a water soluble monomcor such as acrylarnide. 13y water insoluble monomer in th.

context of the precont Gpecification we mean monomer that is soluble in water to a degree of up to 5% at room V temperature. Suitable mniomierc are etyrono and al)kyland/or halo- subistituted styrenes, (meth) acryloniLril., vinyl alkanoates (espocially the acetate), vinyl and vinylidene halides (aAP,-eCI.Aly th'm chloide), hydroxy I. alkyl and alkoxy alkyl (meth) acrylates and alkyl (moth) acrylates. Preferred monomc-rs are styrignp, 2-bydioxy ethyl acrylate, acrylon4.trile, vinyl chloride and vinyl acetate and the alkyl (mueth) acrylates. Preferably at loast Sot by weight of oomponcnt and most prcferably 100t, is alkyl (meth) acryl~ate.. Tn 11 44 1tlie AI~e any alkyl groups may contain .1 to 8 carbon atoms but pi-ticularly preferred TTK~rnom?rs are C1-4 alkyl (ittith) aorylatos such as ncthyl mathacrylate, butyl acrylate or, Monomer Wb is gcnerally prescnt i.n an amount of at least 15%, usually at least 204 and p eezably at least jot, The amount io qtncrally below Bot, uaually below 70% and prefpareihly helovw 6o%.

Normally mononer3 and are free of hyarophb1bi groups R ane; should preferably be C t oonventional low molcular weight monomers.

*Mconnirr whic~h is referred to below as the mallyl ethern, proferably includos a polycthoxy chain and so n is generally above 2, orten ab~ove 5 and frequenatly above 10 or 15 up to 50 or even up to 100.

Thu. a polyoxyethylene chain between the allyl group and tho hydrophobo iu generally prex*en. but it MAy hk- interrupted by oxypropylene and/or oxybutylene groups. By appropriate choice of the valueo of n, and R it is possible Lo control. the sriiity of the monomer and the properties of the final polymer.

RI is gen~erally hydrogen.

X sa hydrophobic group containing at least 8 carbon atoms. It ca~n be a piyoxyalkylenv- k:hemdn wh..hre the alkylen, groups wholly or m~ainly are propylene or butylene or higher but preferably is a hydrocarbyl group, Trhe hydrocarbyl group gencrally contairis from 8 to preferably 10 to 24 and mnost preferably 12 to 18 carbon atomns. it may ba selected from alkylo for inatanee octyl, laury. or stearyl, ai'alkyl 6.uc'h as t %if 2-phenyl ethyl (-C 2 H 4 Ph),a aryl sugh as naphthyl, alkaryl such as alkyl phb-nyl wherein the alkyl group generally I, contains 6 to 12 carbon atoms, cycloalkyl, (including tilt polycyclic alkyl groups), or mixtures of one or more such rt1r grolapo ircferred hydrocarbyl groups are alkyi and "tit alkaryl groups. Any of these groups may additionally be substitulted provided the zubetituont:; do not rendcr thc pendant: qroxup hydrophilic to an extent tOhdt thv (de-J.LeO improvement in propertics aue to the hydrophobic group is lost.

Vi The amount of the allyl other is gonerally at least 3% an6 usually at least it is ge~nerally Lelow 701 and usually bclow 50%. Amounts in the range 5 to are after, ptererred.

Tihe allyl ethers may be foade by mcthods such as tilt thnAA Aescrihed in GB 1,273,552, for in~tivv by rv~t.laq an appropriatc surfactant alc~hol with sodium or sodium alkoxide, cgenerally Jn the Absen;ce of water but in a solvent Euch as xylene, to form tho uodium derivative and thi.n reacting this with ally!. chlox-ide, or by reaqting ally. alcohol with the surfactant alcohol writh or without catalyst.

Vro i

I

11 Monomer is optional and serves as a cross linker. Suitable cross linkers for emulsion polymerised ethylenically unsaturated monomers are well known. They are generally polyethylenically unsaturated monomers materials such as diallyl phthalate, allyl (meth) acrylate, divinyl benzene, (poly)ethylene glycol dimethacrylate and methylene bis acrylamide. If the cross linker is present its amount is generally in the range 0.0005 to 5% (5 to 50,000 ppm), generally below 1%, most preferably 0.001 to 0.2%.

Particularly preferred copolymers are those formed from 20 to 60% by weight acrylic acid and/or methacrylic acid (preferably methacrylic acid alone), 5 to 60% ethyl acrylate or other suitable alkyl (meth) acrylate and 2 to 50% of the allyl ether, optionally with cross linker.

Other preferred polymers are formed from 20 to dialkylaminoalkyl (meth) -acrylate or -acrylamide, 5 to 60% ethyl acrylate or methyl methacrylate or other alkyl S(meth) acrylate, with 2 to 50% monomer and i s 20 optionally i The polymers may have a molecular weight well above million and generally above 1 million, eg above 2 l million and often above 5 million, when they are prepared 1 in the absence of chain transfer agents. This is far in excess of what would be expected from knowledge of allyl polymerisations in general. However for some purposes the highest molecular weights are undesirable because of the risk of flocculation occurring when the thickener is used in a system containing suspended solids.

Accordingly it is sometimes desirable to polymerise in the presence of a chain transfer agent in order to depress molecular weight, eg down to 100000 or 200,000.

The -intrinsic viscosity (namely the single point intrinsic viscosity as measured at 0.05% polymer concentration in methanol) of linear polymers is 12 generally at leasnt 0.5 and when there is no solid phase thu IV is preferably at least 1 and proferably at loact 2o 3 or even 5, for instance it m~ay be 5-10 or hicjher.

Cross linked, emulsion po2.ymericed, polymere are Polymer$ Inade from monomers and under conditions that would, in the absence of cross linker lead to linear polymers having thtse preferred ittulecuulax weight and viscosity properties, The emulsion polymerised polymers of the invention differ from those -of co 1,167,524 and 1,273,552 in a number of respects. They are made by oil-in-water emulsion polymerivation, thic permitting much higher molecular weights. They are insoluble and unswollen aL the pH~ at which they are manufactured, and soluble or 2S &WOllcn at another, 'whereas f~he anionic; polymers of 08 1,1.67,524 are water soluble. The molecular woights that are obtained in the invention can be very mrich higher than anything obtainable in thoise patents, Tho reason for our being able to obtain high moleculair we!iqht.s is not clear but mnay be due to~ thc effect of the group B on the polymr isal~cm pituluettiev iuf the Allyl monomer. The comonomers preferably are such as to permit high molectilAr weights ancn pre~ferably are not such as Lo reduce molecular weight (e.0 maleic anhydride with methyl vinyl ether, as in those p~tpnts).

Other -diclosures of polymere containing allyl ethers 6re, in EP 0172723, 0172724 and 0172025, sivnv o.C which were publichod at the priority date of thin application and all of which, so fttr as the ally1 ether disclosure is conorned, have the came priority date ao this application.

The polymers differ from the polymers disclosed in, for instance* EP 13836 by omittimng the acrylic ester for introducing~ the hydrophobic group and ucing inotcad tho defined ally], ether. it in very surprising that this substitution can be made without seriously reducing the molecular weight and without damaging the properties of the polymer. It is surprising that the polymers have viscosity and other properties at least as good as those of EP 13836 and in many respects better. By the invention the risk of the hydrophobic group being hydrolysed out of the polymer chain by thermal or pH hydrolysis of the ester linkage is eliminated. It is also possible to avoid the other problems outlined above.

The oil-in-water emulsion polymerisation may be conducted in conventional manner, for instance as described in EP 13836. Emulsifier is included to maintain the monomer and the polymer in stable dispersed condition and to provide micelles for the polymerisation.

When monomer is anionic, suitable emulsifiers are anionic, such as sodium alkyl phenyl ether sulphate or sodium lauryl sulphate or sodium dodecyl benzene J r* sulphonate, but may be non ionic. When monomer is cationic, the emulsifier is preferably non-ionic.

20 The initiator is preferably a water soluble initiator, most preferably an alkali metal or ammonium I persulphate, generally in an amount up to 1% based on the monomers. Preferably polymerisation is started and further monomer is then added. The polymerisation i 25 temperature is generally in the range 60 to 100°C.

Although it is generally undesirable, in some instances a chain transfer agent such as an alkyl *mercaptan may be added to the monomer in order to depress molecular weight for example to minimise flocculation during thickening.

*i The amount of monomer, and thus of polymer, in the emulsion is generally from 20 to 60%, most preferably to 50%, based on the weight of emulsion. The emulsion has a pH at which the polymer is insoluble and substantially unswollen in water (7 or below when monomer L I ~Of j. 14 is anionic and 7 or above when it is cationic) but upon addition of alkali or acid (for anionic or cationic polymers respectively) the polymer dissolves or swells and will form a very viscous composition. The polymer can be isolated from the water after or, preferably, before the adjustment of pH by, for instance, spray or drum drying to form a powder or the polymer may be converted to a concentrated, substantially anhydrous, dispersion in a non-aqueous liquid as described in EP 0172025. Often however it is convenient to use the polymer in the form of the oil-in-water emulsion in which it is initially produced. The pH adjustment may be made to this emulsion before use but preferably the emulsion is added to the phase that is to be thickened while the polymer is still insoluble and unswollen and the polymer is converted to a viscous thickener by reaction with alkali or acid in the aqueous phase. The pH of this r aqueous phase may be as high as, for instance, 13 or 14 when the monomer is anionic and as low as 1 or 2 when 20 monomer is cationic.

°The emulsion polymerised polymer is generally supplied to the user as an oil-in-water emulsion but if desired may be converted to a water-in-oil dispersion (or a dehydrated product thereof) before use, as described in EP 172025.

Improved thickening is often achieved in the i presence of a surface active agent, generally in an amount of from 0.05 of 1 part by weight surfactant per part by weight polymer. Surfactants that will give this effect may be selected from anionic, non-ionic, amphoteric or cationic provided they are compatible with the polymer and the other components of the aqueous phase. Preferably they are non-ionic or anionic, Preferred surfactants are ethoxylated linear alkyl ethers or ethoxylated alkyl phenyl ethers. Often the |r~pr-L;lr f:i* U 1. II 1 t i surfactant is the same as or similar to a surfactant alcohol that has been used to form the allyl ether.

The polymers are of particular value for thickening aqueous media containing electrolyte and optionally containing a dispersed phase. For instance the polymers i may be used for thickening chemically toxic aqueous iI compositions. These may be alkaline compositions such as bleaches, caustics and paint removers when monomer (a) is anionic. They may be acidic when monomer is cationic. For instance a cationic polymer may be introduced into an enviornment and then thickened by adding acid.

The polymers (especially when monomer is anionic) are of particular value for thickening aqueous latex paints, both matt, semi-matt and gloss paints.

i These may contain conventional pigments, dispersants and ji :binders.

The polymers (especially when monomer is S ,anionic) are also of great value for thickening textile *IIr 20 print pastes. Such systems include for example reactive j dye or acid dye, or pigment pastes especially where such I pastes are prone to gelling. The other components of the print paste may be conventional. In such pastes they not only have the valuable high shear and low shear 25 viscosity properties that are useful in all thickening situations but they also have the advantage of minimising flushing of the print colour. Particularly good results j are obtained in combination with surfactant.

SOther uses for the polymers are for thickening oils, as water retention aids, eg in cements, and as deicing fluids, for thickening brine downhole), for thickening carpet backing latices and for thickening textile sizing solution.

'SL: ~4 v 7

-L

The amount of polymer used is generally in the range 0.05 to 5% weight based on the water content of the aqueous phase that is to be thickened.

The polymers can be used for other purposes, e.g., as wallpaper adhesives.

The invention also includes water insoluble, acid or alkali swellable or soluble, polymers made by other techniques, polymerisation in solution in organic solvent.

The invention also includes linear polymers which au v hadue irrespective of how they are made a a haing IV of at

A

least 0.5. They may be water insoluble and made from the monomer blends and by the methods described above or they may be water soluble. For instance they may be made from 0.5 to 100% monomer and 0-99.5% water soluble monomers and These may have IV 0.5 to 1 or higher, as described above.

0 Monomer may be as described above. The 'o polymers are preferably non ionic or anionic.

D 00 S°o' 20 The preferred soluble polymers have, as monomers (a) 00a and water soluble anionic monomer optionally blended 0o with acrylamide, water soluble cationic monomer *e a optionally blended with acrylamide, or acrylamide.

Naturally the monomers should be free of pendant S ,s 25 hydrophobic groups. 0-20%, generally 0-10% and *0 preferably water insoluble monomer can be included.

0° One class of preferred soluble anionic copolymers of the invention are formed of 5 to 50%, preferably 20 to 40% acrylic acid or other unsaturated carboxylic or *0 ,o sulphonic acid, generally as a sodium or other salt thereof, 50 to 90%, preferably 60 to 80%, by weight acrylamide and 2 to 30% by weight of the allyl ether.

Another class of preferred soluble anionic copolymers are formed of 50 to (ften 80 of copolymers are formed of 50 toA*3e%- (often 8 of r ,1 lei/iA 7 r r .4 6a~l I O 0 *r o '4+ tr the acid, 0 to 50% (often 0-20%) acrylamide and 2 to of the allyl ether.

Preferred cationic soluble polymers of the invention are formed of 10 to 99% and preferably 20 to 70% dialkyl amino alkyl (meth)-acrylate or -acrylamide quaternary or free acid salt, O to 80% preferably 20 to 70% acrylamide, and 1 to 90%, preferably 5 to 50%, of the allyl ether.

The water soluble polymers can be made by conventional methods of making water soluble polymers but modified by the incorporation of the allyl ether, e.g., as in EP 0172723. Thus they may be made by aqueous gel polymerisation or by reverse phase polymerisation. This process may be conducted to a very small dry particle size, such as below 4 4m, for instance as described in European application 0172724 or may be conducted as a bead polymerisation process, using conventional water soluble initiators, stabilisers and, if desired, emulsifiers. Suitable materials are described in that application. Linear water-soluble products may be made as in either of these specifications in the absence of cross-linking monomer.

The soluble polymers may be provided as dispersions in non-aqueous liquid or as dry pazticles, for instance made by bead polymerisation followed by drying and filtering or made by gel polymerisation followed by drying and comminuting. Depending upon the solubility of the monomers used for their manufacture the polymers will either be truly water soluble or will be water swellable.

These polymers are useful as flocculants, for instance as described in EP 017272. In addition to acting as flocculants for, for instance, sewage or inorganic dispersions they are also of value as filtration aids and paper retention aids, as gangue suppressants as clarification improvers, for pelletising minerals, as dewatering aids or filtration rate improvers as drift controllers in agricultural spray compositions, P? :1Cti- i I :L i-)P FI. I-i Oj

I(

II

I *t 14 I I I **4 It, I 1.'

IIII

as soil stabilisers or dust suppressants, and, especially, as thickeners for aqueous liquids.

They are particularly effective for thickening any of the compositions described above including paints, textile print pastes, or chemically toxic and other aqueous compositions such as bleaches, caustics and paint remover compositions and, especially, for thickening brine, drilling muds and other downhole electrolyte liquors such as for acidising or fracturing, especially when the polymer contains sulphonate groups or cationic groups. Other downhole uses are as viscosifiers for enhanced oil recovery, drilling fluids or shut off fluids, as fluid loss additives, and for polymer flooding. They may be used with surfactant, as described above. The soluble linear polymers may have better suspending properties in respect of large or heavy inorganic particles than the emulsion polymers discussed above.

Another use for the water soluble polymers is as an aqueous adhesive, for instance a wallpaper adhesive that may be a brush-on composition or a prepaste.

The invention also inlcudes cross linked polymers.

They may be non swellable in water but swellable in acid or alkali and so may be made by emulsion or organic solution polymerisation as described above. They may be formed of 0.5 to 100% monomer and 0-99.5% monomers and and 0.0001 to 5% cross linking agent, where all the monomers may be as discussed above for emulsion polymerised polymers.

30 Preferably the cross, linked polymers are water swellable and the monomers and the polymerisation conditions, are preferably such that in the absence of the cross linking monomer the polymer would have IV at least i, generally at least 2 and preferably at least 3, often above 5, for instance 10 to ~r D' 31 I rr

)C

19 Preferred water swellable polymers are formed from 1 to 100% of the allyl ether, O to 99% water soluble monoethylenically unsaturated monomer and O to generally O to 10% and preferably 0% of water insoluble monoethylenically unsaturated monomer. Suitable water soluble monomers are discussed above.

Preferred swellable polymers have, as monomer water soluble anionic monomer optionally blended with acrylamide, water soluble cationic monomer optionally blended with acrylamide, or acrylamide. Naturally the monomers should be free of pendant hydrophobic groups.

One class of preferred swellable anionic copolymers are formed of 5 to 50%, preferably 20 to 40% acrylic acid or other unsaturated carboxylic or sulphonic acid, generally as a sodium or other salt thereof, 50 to preferably 60 to 80%, by weight acrylamide and 2 to by weight of the allyl ether, and cross linking agent.

Another class of preferred anionic copolymers are A 80-/P of the acid, 0 to formed of 50 to (often 80 of the acid, to (often 0-20%) acrylamide and 2 to 30% of the allyl ether, and cross linking agent.- Preferred cationic polymers of the invention are formed of 10 to 99% and preferably 20 to 70% dialkyl amino alkyl (meth)-acrylate or -acrylamide quaternary or free acid salt, O to 80% preferably 20 to 70% acrylamide, and 1 to 90%, preferably 5 to 50%, of the allyl ether, and cross linking agent.

The water swellable polymers can be made by conventional methods of making water swellable polymers but modified by the incorporation of the allyl ether.

Thus they may be made by aqueous gel polymerisation or by reverse phase polymerisation. This process may be conducted to a very small dry particle size, such as r- t 1below 4 am, for instance as described in European application 0172724 or may be conducted as a bead polymerisation process, using conventional water soluble initiators, stabilisers and, if desired, emulsifiers.

Suitable materials are described in that application.

The polymers may be provided as dispersions in non-aqueous liquid or as dry particles, for instance made by bead polymerisation followed by drying and filtering or made by gel polymerisation followed by drying and comminuting.

When the polymerisation is conducted to give a small particle size, for instance below 4 microns dry size, and especially when the comonomers are anionic, especially acrylic acid (for instance as ammonium or sodium acrylate) alone or blended with acrylamide the resultant compositions are particularly useful as textile print paste thickeners.

Anionic water swellable polymers having a particle size of, for instance, 50 to 500 am dry size are *t 20 particularly valuable as absorbents, for instance in diapers or for dewatering slurries or conditioning soil.

Suitable polymers for this purpose are generally formed &lit of 2 to 50% (preferably 3 to 30%) of the allyl ether, 0 to 70% (preferably 30 to 60%) acrylamide and 20 to 98%, S 25 preferably 30 to 50%, sodium acrylate and 0.001 to 0.1% cross linking agent. The polymers may be made by gel polymerisation, drying and comminution to the desired size or by reverse phase bead polymerisation.

Alkali swellable, small particle size, polymers from water insoluble monomers are particularly effective for thickening latex paints and chemically toxic and other aqueous compositions such as bleaches, caustics and paint remover compositions and, especially, for thickeneing brine, drilling muds and other downhole electrolyte liquors such as for acidising or fracturing especially Ilr when the polymer contains cationic groups or sulphonate groups. Other downhole uses include viscosifiers for enhanced oil recovery, drilling fluids or shut off fluids, as fluid loss additives, and for polymer flooding.

Other uses for the water swellable polymers is as an aqueous adhesive, for instance a wallpaper adhesive that may be a brush-on composition or a prepaste, as deicing fluids, or as water retention aids.

When the polymer is present as water swellable beads the surface of the particles is preferably less swellable than the inner parts of the particles, preferably as a result of cross linking the surface layer in known manner U.S. 3,114,651, 4,043,952 or 4,090,013. This treatment can reduce the stickiness of the particles and can improve the absorption properties.

SThe following are some examples.

Example 1 An emulsion of momomers in water was prepared by S 20 mixing lOOg of ethyl acrylate, 80g of methacrylic acid, 20g of allyl ether of 10 mole ethoxylate of stearyl Salcohol, 5g of Perlankrol ESD (trade mark), 0.3g ammonium persulphate and 200g water. To a reaction vessel containing 2.5g Perlankrol ESD, O.lg ammonium persulphate in 255.8g water at 85 0 C, degassed for 30 minutes with nitrogen there was added 5% of the monomer emulsion over a period of 10 minutes.

After the initial charge had polymerised at 850C, the remaining monomer emulsion was gradually added over a period of two hours at 85 0 C. After completion of the monomer feed, the mixture was held at 850C for 15 minutes and then lOg of 1% ammonium persulphate solution was added. After another 45 minutes, the mixture was cooled and filtered.

-T I 11-, 1 -I I I The filtrate was approximately 30% solids emulsion copolymer in which the polymer composition is 10% of the allyl ether, 50% ethyl acrylate and 40% methacrylic acid.

The polymer thus prepared was designated Product A.

Further samples of varying composition were prepared using this procedure. These were designated in turn as Products B-U. Solutions in water were prepared by neutralisation with ammonia to pH 7 or above and the resulting viscosity was measured using a Brookfield RVT viscometer. This data along with composition variables is given in Tables la, lb, and Ic.

Note In table 1 MAA methacrylic acid EA ethyl acrylate AES allyl ether surfactant of formula CH =CR'CH OB R 2 2 n where R' H B (CH2-CH2-0) and n and R are as stated.

20 In table la POLYMER H was prepared without using an allyl ether surfactant monomer. This therefore served as a control.

*0 *D 0 000 *900 0 00 0 4 0 I r t i t t -ILr 'i Table la PRCOU3CT MONOM1ER RATIOS SURFACThNT COMPOSITIONS SOLUION by wt) VISCOSITY (cp) l0rpn MAA EA PIES n R POLYMER A 40 50 10 10 Stearyl 14000 POLYMER.B 40 50 10 2 Stearyl 8400 POLYMER C 40 50 10 20 Stearyl 7200 POLYMER D 40 50 10 4 Lauryl 150 POLYMER E 40 50 10 23 Lauryl 600 POLYMER F 40 50 10 30 C 22 140000 POLYMER G 40 50 10 25 Octyiphenyl 500 POLYMER H 40 60 00 0 *00 0 00 4 0 00*0 4 0 0000 00 *0r.4 0 0 00~* 4 04 0 00 0 00 0 0 0 @04 0 Note: n dodecyl mercaptan was included in each of the above recipes, at 0.2% on total monomer.

c I- ir

-~-LII

Table lb PRODUCT MONOMER RATIOS SURFACTANT COMPOSITIONS SOIDTIO by wt)

VISCOSITY

(cp) MAA EA AES n R POLYMER J 40 55.0 5.0 10 Stearyl 1280 POLYMER K 40 52.5 7.5 10 Stearyl 20800 POLYMER L 40 50.0 10.0 10 Stearyl 26200 POLYMER M 40 47.5 12.5 10 Stearyl 38000 POLYMER N 45.0 15.0 10 Stearyl 53600 POLYMER P 40 42.5 17.5 10 Stearyl 72000 POLYMER Q 40 40.0 20.0 10 Stearyl 93200 Note: n dodecyl mercaptan was included in each of the above recipes at 0.1% on total monomer.

Table Ic PRODUCT MONER RATIOS SURFACTANT CCMPOSITOINS SOUJIOIN by wt)

VISCOSITY

(cp) MAA EA AES n R POLYMER L 40 50 10 10 Stearyl 100000 POLYMER R 30 60 10 10 Stearyl 31000 POLYMER S 25 65 10 10 Stearyl 15800 POLYMER T 20 70 10 10 Stearyl 12200 POLYMER U 15 75 10 10 Stearyl 260 0004 o *0 *0 0 and 0 0 00.W *O 0 o S 0 0 S 0 Note: n dodecyl mercaptan was included in each recipes at 0.1% on total monomer.

Example ld of the above r x~ The effectiveness of polymers AA-AF prepared from other alkyl (meth) acrylate/carboxylic acid monomers is shown.

Table Id 0 0 0 0* o o C +0 e o 4« 4 e* e fl 0 06 9* o Monomer Ratio by wt.) Solution Product Viscosity MAA AA IA MA EA BA MMA AES (cP) at 10 rpm Polyner AA 40 50 10 76300 Polymer AB 40 50 10 2400 Polyer AC 35 5 50 10 42400 Polymer AD 30 10 50 10 11300 Polymer AE 37.5 2.5 50 10 48000 Polyner AF 40 25 25 10 2940 Note: n-dodecyl mercaptan was included in each of the above recipes at 0.1% on total monomer.

The abbreviations used to denote the monomer are as 20 follows:- MAA methacrylic acid AA acrylic acid IA itaconic acid MA methyl acrylate 25 EA ethyl acrylate BA butyl acrylate MMA methyl methacrylate AES allyl ether surfactant as previously defined with n=10 and R=stearyl.

Example 2 The influence of electrolyte on the thickening efficiency of. products of this type was investigated.

Three polymers, having compositions as described below were prepared as 2.0% active solutions in deionised water and 0.5% Nacl solution. Solution viscosities were 26 measured using a Brookfield RVT viscometer over a range of speeds as indicated.

POLYMER V: As POLYMER A but without n-dodecyl mercaptan POLYMER W: As POLYMER v but with 250 ppm diallylphthalate.

POLYMER X: As POLYMER H but with 250 ppm diallylphthalate Table 2 a i i: -j i p pI p 4i 4*a 4 4I "e 4I 4 44 4 *4 PRODUCT 2.5 rpm 10 rpm 100 rpm

H

2 0 0.5% NaCl H20 0.5 NaCl H20 0.5% NaCI POLYMER V 200000 272000 130000 180000 28500 35000 POLYMER W 284000 240000 180000 85000 25000 22000 POLYMER X 150000 11200 22000 3700 4200 680 Polymer X having no allyl ether surfactant monomer 20 was present to serve as a control.

Polymer V had intrinsic viscosity of 2.5 measured by single point method in methanol at 0.05%.

Example 3 The influence of additional surfactant on the thickening efficiency of products of this type was investigated. To 2.0% active solutions of POLYMER A was added increasing amounts of various surfactants. The solution viscosity was remeasured after each addition, and is listed in Table 3 as an index relative to the 30 initial viscosity in the absence of surfactant.

I 1.

27 Table 3 SURFACTANT TYPE SURFAC'ANT CONCENTRATI 0.1% 0.2% 0.3% Lauryl alcohol.4 ethoxylate 188 258 271 Stearyl alcohol.10 ethoxylate 104 115 135 Sodium Lauryl sulphate 163 625 798 Sodium C12-C15 alcohol ether sulphate 149 214 244 Example 4 To demonstrate the greater stability attained by linking the hydrophobe through an ether linkage rather than an ester linkage, and to eliminate variables due to other monomers in the polymer, a comparison was conducted between the hydrolytic stability of the ester of acrylic acid with polyoxyethylene (23 moles) lauryl ether and of the ether of the same lauryl ether with allyl alcohol (formed by reacting the sodium derivative of the ether with allyl chloride).

A 2.0% solution of each monomer was placed in a thermostated water bath at 45 0 C. Each was taken to pH 11.0 with 0.0986 M NaOH. The pH was checked every hour and readjusted to pH 11.0 by the addition of further NaOH. The volume of NaOH required was noted and hence the percentage hydrolysis was calculated for each monomer.

S Table 4 r4 t F *l

II

I t^ *Itl .1 TIME ACRYLATE MONOMER ALLYL ETHER MONOMER hours Vol Na (can 3 Hydrolysis Vol NaOH (an 3 Hydrolysis 0 1.05 0 1.00 0 1 6.75 37.0 0 0 2 12.70 69.7 0 0 3 18.10 99.3 0 0 From this it is apparent that the allyl ether linkage is much more chemically stable than the acrylate linkage.

Example In order to demonstrate the usefulness of polymers of this type for thickening aqueous alkaline solution eg caustics and paint removers, solutions of POLYMER A and POLYMER F were prepared 2.0% active in 10% NaOH solution.

20 The resulting solution viscosities were measured using a Brookfield RVT viscometer over a range of speeds.

Table PRCDUCT BROCKFIELD VISCOSITY (cp) rpm 10 rpm 20 rpm 100 rpm POLYMER A 52000 24500 16000 4600 POLYMER F 54000 16500 9000 2500 This clearly demonstrates the high level of thickening efficiency which polymers of this type are able to exhibit in such systems.

1 II eo ii 29 Example 6 Emulsion Paints Two matt emulsion paints (MEP1 and 2) were prepared using polymers according to the invention and one (MEP3) using a conventional paint thickener Natrosol 250 HR*.

Each paint was made to 65% pigment volume concentration from the following "Mill Base" and "Let Down" recipes.

Mill Base Parts by weight Water 15.001/19.302 Dispersing agent 0.46 Bactericide 0.05 Hexylene glycol 1.00 Defoamer 0.05 Thickener 1.001/0.302 0.880 ammonia 0.20 Titanium dioxide 19.75 Calcium carbonate 19.75 I Talc 6.59 A Let Down S 20 Latex binder 16.18 0,#0 Coalescing solvent 0.80 'Water 18.77/15.372 0.880 ammonia 0.40 1. Quantity used with aqueous thickener of the 25 invention in paints MEP1 and 2.

'2 2. Quantity used with conventional thickener in paint MEP3.

*Natrosol is a trade mark.

The components of the "Mill Base" were milled under high shear at 2290 rpm to Hegman Gauge 7-8. The i components of the "Let Down" were then added at a reduced speed of 890 rpm. The paints were then stored for a period of 7 days at room temperature before characterisation.

6 0. I Table 6 44 4r 4 4 44 4 44 4 i I 44 Paint Thickener Final Brookfield Stormer ICI Rotothinner Sanple dry pH RVT 20 rpn Viscosity Viscosity Code on total) (Poise) (Krebs (Poise) Units) MEP-1 POLYMER A 9.0 120 108 MEP-2 POLYMER W 9.0 252 121 10.0 MEP-3 NATROSOL 250HR 9.1 120 105 7.6 Each of the above points was evaluated for its spatter properties using the following test procedure.

15 A board, approximately 30 x 42 cm was mounted vertically above a work bench the bottom edge being positioned 20 cm above the surface of the bench. A piece of black card measuring 24 x 31.5 cm was then placed on the surface of the bench top directly below the board in 20 order to catch any droplets or "paint mist" spattering from the roller.

Each paint was poured in turn into a roller tray and applied to the vertical board using a lambswool roller.

The standard conditions adopted for this test involved upstrokes and downstrokes of the roller on the board.

The black card was then removed for inspection. The degree of spatter was assessed visually and rated on a scale of 1-5 with 1 being excellent; ie no spatter and being very poor; ie severe spatter. The results recorded were as follows: Paint Sample Code Spatter MEP-1 2 Very Good MEP-2 1 Excellent MEP-3 4 Poor Example 7

A

6W.. _I 31 Carpet backing formulations The use of products of this type as thickeners for carpet backing formulations has been demonstrated according to the following information.

Formulation A B Total Solids (nominal) 76% Filler: Binder Ratio (dry:dry) 8:1 1:2 Latex Binder (50% active) 15.6 49.5 Calcium carbonate filler 67.5 13.0 Surfactant 0.1 0.1 Dispersant 1.0 i Thickener Water to 100 to 100 The amount of thickener was selected such that i Formulation A had viscosity 9000cp and B had viscosity 6000cp, Brookfield RVT viscometer, spindle 5 at 10 rpm.

S In this instance Polymer E fully neutralised as Na+ S salt was compared as thickeners with VISCALEX AH lif" <(carboxylated acrylic gel polymer sold by Allied Colloids i Limited as a thickener for carpet backing compounds).

The following results were obtained.

I It ii

I

11--_1_1 Table 7 4 *4 4 4 *t I 444: 41

II

44 t 4414c BROCKFIEID VISCOSITY (CP) FORMUIATION A FORMUIATION B THICKENER TYPE Viscalex AH10 Polymer E Viscalex AH10 Polymer E ADDITION LEVEL 0.16 0.035 0.90 0.15 Dry on Total) Initial Viscosity 9100 8600 5800 6000 Day 1 Viscosity 9000 8600 5600 6200 15 Day 2 Viscosity 9000 8600 5800 6200 The improved level of effiency of the polymers of the invention is clearly deomonstrated.

Printing Pastes 20 In the examples which follow, all print paste viscosities were measured with a Brookfield RVT viscometer at speed 10 rpm, spindle 6 at 200C. Printing was carried out using a variety of screens, each being constructed of 156 mesh polyester filament.

25 Example 8 A printing clear was prepared according to the recipe given in Table 8.

_R

33 Table 8 COMPONENT by wt Ammonia (0.880) Emulsifier* Odourless kerosene 40.0 Binder latex (40% solids) 12.0 Polymer W 1.7 Water 43.8 ethoxylated nonyl phenol (14 moles ethylene oxide) SA viscosity of 20,000 cp was obtained after stirring for 10 minutes. The clear was then divided and pigment i printing pastes prepared by mixing 9.6 parts of this S stock with each of the following pigments: Imperom Blue KRR 4 parts (ii) Helizarin Bordeaux R 4 parts These pastes were then re-thickened by stirring in additional quantities of Polymer W until a viscosity of S20,000 cp was again obtained. The amounts of Polymer W required were found to be 0.19 parts and 0.23 parts for the blue and bordeaux pigments respectively.

Both pastes were printed on to a plain woven 50/50 cotton fabric. The prints were then dried and cured for minutes of 150°C. In each case excellent colour Syeild, brightness and find line definition were observed.

Example 9 A series of printing clears was prepared in which the concentration of Polymer A was progressively increased. The recipes are given in Table 9a below, where all figures refer to parts by weight:

V.-

34 Table 9a

V

Li 11 ii Paste A B C D Component Ammonia (0.880) 0.5 0.5 0.5 Binder latex (40% solids) 12.0 12.0 12.0 12.0 Water 85.88 85.65 85.56 85.21 Thickener' 1.62 1.60 1.44 1.29 Polymer A 0.25 0.50 1.00 The thickener used was a 50% active dispersion of a cross-linked polyacrylic acid such on described in US 4554018. In each case the concentration employed was chosen so as to give a viscosity of 20,000 cp.

Printing pastes were then prepared from each clear by mixing 96 parts with 4 parts of the following black pigments and stirring by efficient mechanical means for 20 5 minutes.

Imperon Black KGF s (ii) Acramin Black FBRK The viscosity of each paste was then remeasured at 0 C. The results were as follows: I- 3- Table 9b .9 o *9 9 *a C es. a PASTE VISCOSITY (cp) Black KGF Black FBRK A 50,000 66,000 B 29,400 30,600 C 23,000 25,200 D 19,600 20,200 The two pastes A, prepared without the addition of PcJymer A, were highly viscous gels and were considered unsuitable for practical use. As the concentration of Polymer A was increased, the increase in viscosity, compared .with the initial clears, was greatly reduced.

All pastes B, C and D were of the correct rheology for commercial printing.

Example 20 Printing pastes were prepared using Polymer A and a cross-linked polyacrylic acid thickener in an analagous manner to that outlined above. The recipes were as follows, all figures referring to parts by weight.

1 I _IIII_ IIII_ RC_ IIII1I.CI_--__l~-- -i Table a.

4., a a *a 0 a 4 t* Si ta Paste A B C D E F G H Cmponent Amonia (0.880) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Binder latex 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0 Water to 100% Thickener 1.62 1.61 1.44 1.29 1.65 1.84 1.82 1.79 Polymer A 0.25 0.5 1.0 0.25 0.5 Inperon Blue KRR 4.0 4.0 4.0 4.0 Helizarin Bordeaux R 4.0 4.0 4.0 15 Each paste was printed on to a substrate which was known to cause severe flushing or haloing when printed with many existing formulations. The fabric chosen was a plain woven 50/50 polyester/cotton which had been preresinated using a DHDHEU resin and also contained a magnesium chloride catlyst.

The severity of flushing was critically assessed by using a printing screen which consisted of a series of five lines and criss-cross patterns. Immediately after printing, the fabric was allowed to dry for 2 minutes under atmospheric conditions before being dried at 150°C for 2 minutes (drying quickly causes the movement of print paste to be halted).

The extent to which flushing occurred was then assessed on an arbitary 1-10 scale, where 1 indicates a perfect print without any sign of flushing and indicates severe flushing. The results are given below:

_I

i i ~II1 ~I i Table t litr PRINT PASTE BLUE PASTE BORDEAUX A 8 E 8 B 5 F 3 C 3 G 3 D 2 H 2 The inclusion of Polymer A into the printing paste is clearly seen to bring about a dramatic improvement in print quality, with a 1% addition virtually eliminating flushing. It is considered that a rating of 3 or below would represent a commercially acceptable print.

15 Example 11 A latex was formed by oil in water emulsion polymerisation using ammonium persulphate of 40 parts by methacrylic acid, 50 parts by weight ethyl acrylate and parts by weight of a surfactant ether formed from allyl chloride and the reaction product of polyoxyethylene (10 moles) stearyl ether with sodium methoxide.

200 grams of the latex was homogenised into an oil phase comprising 7.0 grams of Span 80, 23.3 grams of a 30% active solution of a 2:1 molar copolymer of ceto-stearyl methacrylate:hydroxyethylmethacrylate in SBP11, 39.2 grams of Pale Oil 60 and 96.0 grams of SBP11.

The resulting inverse emulsion was then dehydrated by distilling off water and SBP11 under reduced pressure to a final pressure of 10 mm.Hg and a temperature of 95 0

C.

The resulting anhydrous polymer-in-oil dispersion was activated by mixing in 5.6 grams of Ethylan D254 to produce a self-emulsifiable liquid polymer-in-oil dispersion having 50% active solids. Span and Ethylan are trade marks.

Upon addition of this dry dispersion to deionised water or 0.5% NaCl solution to form a 2% solution, the Brookfield viscosity at spindle 6 is 352,000 or 480,000 cps respectively at 2.5 rpm and 28,000 or 35,000 cps at 100 rpm.

Example 12 The process of Example 1, for Polymer A, was repeated except that the free acid monomer was replaced by a free base monomer as indicated in Table 12a. The Perlankrol surfactant was replaced by Ethylan HA (non-ionic).

Polymers having the compositions indicated in the table below were prepared at 1% active in water by neutralisation with HC1, and the resulting viscosity was S.

*r r 15 measured using a Brookfiled RVT Table 12a viscometer.

Surfactant Solution Product Moncmer Ratio by wt.) Composition Viscosity S (cP) 10 rpm DMAEMA NMA AES n R Polymer AH 45 35 20 10 stearyl 29000 Polymer AJ 50 30 20 10 stearyl 68000 Polymer AK 55 25 20 10 stearyl 136000 Polymer AL 60 20 20 10 stearyl 80000 Polymer AM 40 35 25 10 stearyl 74000 Polymer AN 40 30 30 10 stearyl 27000 Polymer AP 40 25 35 10 stearyl 5200 Polymer AQ 40 20 40 10 stearyl 1700 -DMAEMA dimethylaminoethylmethacrylate MMA methylmethacrylate AES allyl ether surfactant I .li I In order to demonstrate the effectiveness of polymers of this type in thickening highly acidic media Polymer AH was used to thicken 15% solutions of different acids at 5% active polymer. The results obtained are given in Table 12B.

Table 12b #0 00 000 #040 0 0 0 00 0r 00 0c 0 0000 0 44 O 4 4 4001 0 SC 0 4 O COPs! I i Lls Product Acid Type Solution (solution conc 3 w/w) Viscosity (cP) 10 rpm Polymer AH 15% hydrochloric acid 2,200 Polymer AH 15% phosphoric acid 6,400 Polymer AH 15% acetic acid 9,600 This polymer is useful for thickening aqueous acidic liquors, such as battery liquids.

Example 13 181.8 parts of a 79.2% solution of acrylic acid in water, 0.4 parts of Tetralon B, 5.8 parts of the allyl ether of a 10 mole ethoxylate of stearyl alcohol, 118 parts of water, 0.0424 parts of AZDN and 116 parts of a 29.9% solution of ammonia in water were mixed to form an aqueous solution. A non-aqueous liquid phase was formed from 7.4 parts of Span 80, 42.4 parts of a 30% solution in SBPll of an inverse dispersion stabiliser (copolymer of 2 moles cetostearyl methacrylate with 1 mole of methacrylic acid), 127.3 parts of Pale Oil 60 and 145.7 parts of SBP11.

The aqueous phase was homogenised into the oil phase, deoxygenated and polymerised using 0.042 parts of sodium metabisulphite dissolved in 2.058 parts of water and tertiary butyl hydroperoxide added continuously as a solution in water at a rate of 0.14 parts per minute.

The resulting inverse dispersion of hydrated polymer was distilled to yield a dehydrated concentrated polymer dispersion to which was added 2 parts of a 5 mole ethoxylate of nonyl phenol and 1 part of a 4 mole ethoxylate of a broad cut lauryl alcohol per 100 parts of concentrated dehydrated dispersion.

This formed a dispersion of 50% active copolymer which dispersed with agitation in water to yield a highly viscous polymer solution with the characteristic 'soap gel' rheology of associated water soluble polymers.

This process was repeated except that the aqueous phase ,contained in addition 0.063 parts of methylene bis 15 acrylamide as bi-functional crosslinking comonomer. The resultant dehydrated polymer particles swelled in water to form a highly viscous but non-viscoelastic paste useful as a vehicle for printing textiles and other articles particularly on cloth containing residual electrolyte where pastes thickened with conventinal polyammonium acrylate microgel latices give holoing, bleading or flushing of print colour.

Polymers produced by this method but omitting the cross-linking monomer may be made and may be as exemplified in EP-A-0172724.

Examiplp14 A range of polymers were made by gel polymerisation using differing amounts of acrylamide, sodium acrylate, allyl ether and cross linking agent, and by using different ally" ethers. The product of the polymerisation was then dried and comminuted to give particles having sizes in the range 200 to 500 microns.

g of each polymer was added to 400 cc of a swelling solution that was deionised water or aqueous sodium chloride of various concentrations. The samples *tA .7 41 were allowed to equilibrate for 30 minutes and the swollen gel particles were then separated from the medium by filtration'through a nylon filter mesh and weighed to give an indication of absorbency. The values are expressed in percentage based on the amount of deionised water that was absorbed by each polymer. The monomer feed and the results are shown in the following table.

In this table R is the hydrophobic group and n is the number of ethylene oxide groups between it and the allyl ether linkage.

41 0 I *4 o1 4 4+ Polyner 1 2 3 4 5 6 7 8 Acrylamide 60 50 45 45 50 50 50 Sodium Acrylate 40 40 40 40 40 40 40 Methylene bis acrylamide 0.03 0.06 0.06 0.06 0.03 0.06 0.03 0.06 Allyl ether 0 10 15 15 10 10 10 R C 18

H

3 7

C

1 8

H

3 7 C18H37 C 1 2

H

2 5

C

12

H

2 5

C

18

H

3 7

C

1 8 3 7 n 10 10 20 23 23 20 Deionised water 100 100 100 100 100 100 100 0.1% NaCl 21.7 32.4 25.5 33.8 27.3 21.8 25.1 34.0 0. NaCl 12.5 22.4 16.7 22.9 18.8 14.9 16.6 23.8 NaCl 10.3 16.5 11.6 14.9 15.1 11.6 11.9 17.4 1% NaCI 7.9 8.8 10.0 11.2 11.6 7.9 9.8 13.6 Comparison of polymers 3 and 4 shows the advantage that follows from increasing the length of the ethoxy chain.

Very poor results are obtained when there is no ethoxy chain, as in U.S. 4,190,562.

Linear water-soluble polymers may be made as in this example but omitting the cross-linking monomer. Thus they may be as exemplified in EP-A-0172723.

Claims (11)

1. A polymer U6leoted from polymers that are cubstantially non $Welling and insoluble in water but soluble or swIel1able in aqueous acid or alkali and cross linkced polyrr and~ which polymer is forwed by polyme~rising 0 to got by weight of athylenically unsaturated ionic monomer 0 to 904 by weight of ethylanically uneatUrated substantially non-ionic monomor I. to 1004; by weight of an othylenitcally UnSatUrdt..d monomer that carries a pendant group B~R where B is ethylenoxy, n is zero or a positive intager, and R i3 a hydrocarbyl group of a to 30 carbons selected from alkyl, aralkyl, aryl, alkaryl and oycloalkyl is 0 to 5% by weight of cross linking agent theit. is polyethylenically unsaturated monomer, charactericed in that roiiomers a, h, c &nd d Are. mixed before the pelymeriaatlon and that mcrnvmer is an ally. ether of the formula CH, CRICH 2 OBR where~ R' is hydrogen or methyl,

2. A polymer according to claim 1 in which monomer (a) comprises a vinyl carboxylic acid monomer.

3. A polymer acoording to claim 2 in which nonorner is selected frrom acrylic acid and methacrylic acid and 'mixtures thereof. 4, A polymer according to claim I in wldtvii monomer (a) comprises a vationic monomer, A polymer according to Claim 4 in wich:l monomer Is sp1~:~eiIfrom dialkylaminoalkyl (moth) acrylate monomers anid dialkylaminoalkyl (meth) acrylamide monomerw. j r6. A polymer according to any prceding claim in which, in mionomecr R' is1 hydrogen and n is from 5 to 100.

7. A polymer aecording to any preceding claim in which, in monomer R contains 10 to 24 carbon atoms and le selected from alkyl and alkaryl. a. A poly~er Acrdinj to any preceding claim m~ade by oil ina water polymerisation of 5-90% monomer 5-901k monomer 1-90 monomer and 0-5% crosslinking agent.

9. A polymer according to clain 8 formed from 20 to by weight acrylic acid and/or methacrylic arn1,d, 5 to 60% b~y weight ethyl acrylate and 2 to 50k by weight of the allyl If ether, and 0 to 5% cross linking agent. A polymer according to any preceding claim in which monomer is present and is selected from styrene, alkyl- substitut~ed xtrrenArp, halo-substitutei syrenos, (moth) acrylonitrile, vinyl alkanoatcs, vinyl halides, vinylidene halides, hydroxy alkyl (meth) acrylidtes, alkoxy alkyl. (meth) acrylates and alkyl (moth) acrylates. 11, A polymer accordinig to claim 10 In which monomer (b) is is selec-ted from alkyl (moth) acrylates. ig, A polym~er according to any preedinj claim In which the said cross linking agent was present during the polymerisation in an amiount of up to 0.2% by weight.

13. A polymer according to claim 12 that is water soluble and formed from 50-98t water soluble ionic or non ionic mnonomers and 2 to 504 monomer

14. A polymer according to claim 12 formed from acrylic acid or dialkylaminioalkyl (moth)-acrylato or -acrylamide, and 0-si04 acrylanide, and 2 to 50% of monomer

15. Use of a polymer according to any preceding claim for thickecning an aqueous composition..

16. A ciumposition comprising a polyner according to claim a or claim 9 and vhich is in the form of an aqueous emulsion at a pH such that the polymer is incoluble and cubatantiaily umvwollen and non thicki-ning but can be U converted to a dissolved or swollen and thickening otate by the addition of acid or alkali.

17. A composition comprising a polymor according to claim 6 or claim 9 and that is at a pIT such f.ha~t the polyner is 3S dinasolvei or swollen and the composi~tion is thickened by the polyzer. K 44 K 18S. A composition acco~rding to claim 16 selected from V print pastes And emulsion paint*, K 1S. A composition acCording to any of claim 16 to 1s and which als~o contains surfactant ini an amount ofE 0.05 to i. s part per part by woiqht polymer. A polymer substantially as hereinbefore described with reference to the Examoles.

21. A composition substantially as hereinbefore described with reference to the Examples. 0 ooDATED this 30th day of April, 1991. ALLIED COLLOIDS LIMITED By its Patent Attorneys DAVIES COLLISON